The Bears signed linebacker/defensive end Aaron Lynch, who played the past four years for the San Francisco 49ers. Here’s a closer look at the signing:

Injuries have slowed Aaron Lynch in recent years after he totaled 12.5 sacks in his first two NFL seasons. Cary Edmondson/USA TODAY Sports

Grade: C. Lynch tallied 12.5 sacks over his first two seasons with the 49ers but appeared in just 14 games (three starts) in 2016-17. The move reunites Lynch with Bears defensive coordinator Vic Fangio, who coached in San Francisco during Lynch’s rookie year.

What it means: Lynch joins Leonard Floyd and Sam Acho in Chicago’s outside linebacker rotation; that position underwent a massive overhaul in the offseason with the release of veterans Pernell McPhee and Willie Young. The Bears hope Fangio can once again bring out the best in Lynch, who has shown potential when healthy.

What’s the risk: Health. Lynch just turned 25 last week, but he has battled ankle, calf and back issues. The Bears have been burned in the past by signing free agents with questionable health histories; the good news here is that they gave Lynch only a one-year deal. Chicago’s decision to sign Lynch is understandable, since there aren’t many elite pass-rushers in the 2018 draft class.

Grade: B. A sixth-round draft choice of the Bears in 2014, O’Donnell averaged a career-high 47.0 yards per punt in 2017. The Miami product also tied his career best with a net average of 39.7. Multiple teams expressed interest in O’Donnell, who received a one-year deal.

What it means: After signing kicker Cody Parkey to a lucrative deal, the Bears opted for continuity at punter. O’Donnell -- nicknamed Megapunt -- has a strong leg, and he also dropped 27 punts inside the 20-yard line last season. It’s kind of surprising the Bears committed to the 27-year-old only for one more season. He’s one of the club’s most productive players -- along with cornerback Kyle Fuller and left tackle Charles Leno Jr. -- from its 2014 draft class.

What’s the risk: Low. O’Donnell is a pretty good kicker. He’s missed only one game in his NFL career.

The Chicago Bears agreed to terms with veteran quarterback Chase Daniel, who played the past year for the New Orleans Saints. Here's a closer look at the signing:

Grade: B-plus. Daniel has all sorts of ties to the Bears. The veteran backup was directly coached by new Bears head coach Matt Nagy (formerly the Chiefs' quarterbacks coach) for three seasons in Kansas City (2013-15). Before that, Daniels overlapped with Bears general manager Ryan Pace in New Orleans (2010-12). Daniel has minimal NFL starting experience, but he probably knows Nagy's offensive tendencies as well as anyone. This type of signing makes sense on multiple levels.

What it means: The Bears prioritized finding a veteran to back up incumbent starter Mitchell Trubisky. Daniel is a much better No. 2 quarterback option than Mike Glennon, whom the Bears will soon release, because of the familiarity level he has with Nagy's system. Pace also said at the NFL combine that Mark Sanchez, who was Chicago's third quarterback in 2017, had expressed interest in returning to the Bears. Chicago is clearly trying to surround Trubisky with as many experienced voices as possible.

What's the risk: Low. In the event Trubisky gets injured, the Bears are better off going with Daniel -- a nine-year NFL veteran -- over an unproven rookie. Daniel is already ahead of the curve because of his relationship with Nagy.

The Chicago Bears agreed to terms on a two-year, $7.5 million deal with outside linebacker Sam Acho, who played the past three years for the Bears.

Grade: B. Acho’s new contract with Chicago -- as first reported by Acho’s brother, ESPN college football analyst Emmanuel Acho -- represents a greater commitment on behalf of the Bears. Acho played the past several seasons on one-year, minimum deals. Chicago originally planned for Acho to be a reserve player in 2017, but the seven-year NFL veteran finished the year with 40 tackles and three sacks in 12 starts.

What it means: Acho again has an opportunity to play a sizeable role on defense. Chicago released Pernell McPhee and Willie Young in the offseason, paving the way for Acho -- or potentially a draft pick -- to play heavy snaps opposite Leonard Floyd, who’s still recovering from knee surgery. Bears defensive coordinator Vic Fangio clearly trusts Acho, who’s started 57 career games for Chicago and Arizona (2011-14).

What’s the risk: Low. Acho isn’t making a ton of money -- relatively speaking -- but he’s been a reliable contributor in Chicago’s outside linebacker rotation the past three seasons. Beyond that, Acho is a vocal and popular leader inside the Bears locker room, who’s done some amazing philanthropic work over the years.

The Chicago Bears agreed to terms with cornerback Prince Amukamara, who played for the club last year. Here’s a closer look:

Prince Amukamara started 12 games and recorded seven pass breakups for the Bears in 2017. Quinn Harris/Icon Sportswire

Grade: B-minus. The move makes sense. The Bears applied the transition tag to Kyle Fuller last week, but Chicago’s other cornerback spot -- occupied by Amukamara in 2017 -- was wide open. While Amukamara failed to intercept a pass for the second consecutive season -- the inability to take the ball away is probably his biggest downside -- the seven-year veteran played adequately enough to start 12 games. Amukamara, 28, finished second on the Bears’ defense with seven pass breakups.

What it means: Amukamara is extra insurance in the event Fuller signs an offer sheet the Bears choose not to match -- Fuller’s one-year transition tag is valued at $12.9 million. Keeping Amukamara around is not expected to prevent the Bears from drafting a cornerback with the eighth overall pick. Most draft analysts believe Ohio State cornerback Denzel Ward will be a top-10 pick. Re-signing Amukamara, however, takes some pressure off the Bears. Chicago could decide to take a pass-rusher, or even Notre Dame guard/tackle Quenton Nelson in the first round.

What’s the risk: The only risk attached to Amukamara is that he doesn’t take the ball away. That’s a problem. Amukamara is a good player and excellent inside the locker room, but teams prefer defensive backs that force turnovers. Still, Amukamara isn’t a risky signing. The Bears actually played it safe by bringing him back.

The Bears agreed to terms on a four-year deal with wide receiver Taylor Gabriel, who played the past two years for the Atlanta Falcons. Here’s a closer look at the signing:

With his blazing speed, Taylor Gabriel should be a downfield threat for QB Mitchell Trubisky. Dale Zanine/USA TODAY Sports

Grade: B. Having lost out on Albert Wilson, who’s expected to join the Dolphins, the Bears were looking for another free-agent wide receiver to complement Allen Robinson. Gabriel is only 5-foot-8 and 165 pounds, but he was an explosive player under Kyle Shanahan in Cleveland and Atlanta. Gabriel is known to possess blazing speed. If healthy, Gabriel could be a serious downfield threat for Bears quarterback Mitchell Trubisky.

What it means: Gabriel hates being labeled as a slot receiver, but he’s likely to line up frequently inside -- Robinson, Cameron Meredith (if healthy) and Kevin White (if healthy) are better built to play outside. But Gabriel has a strong upper body -- despite his relatively small overall stature -- so the idea of Chicago moving him around isn’t out of the question. Gabriel’s arrival could mean the end for Markus Wheaton, who’s due $5 million in 2018 and none of it is guaranteed. Wheaton was supposed to stretch the field for the Bears last season but never developed on-field chemistry with Trubisky.

What’s the risk: Gabriel suffered a foot injury last summer and didn’t seem the same player during the 2017 season. Part of that could be because Shanahan left for San Francisco and new Falcons playcaller Steve Sarkisian didn’t to use Gabriel the same way. But there will always be some durability concerns with smaller players.

The Bears agreed to terms with Parkey, who played the past year for the Miami Dolphins.

Cody Parkey converted 91.3 percent (21 of 23) of his field goal attempts for the Dolphins last season. Jasen Vinlove/USA TODAY Sports

Grade: B. Parkey, who kicked for new Bears special teams coordinator Chris Tabor in Cleveland in 2016, converted 91.3 percent (21 of 23) of his field goal attempts for the Dolphins last season. Parkey also made 80 percent (20 of 25) of his field goals for the Browns two seasons ago. The fact Tabor signed off on the deal is encouraging. Tabor, who used to work under Dave Toub, is highly respected in the NFL special teams community.

What it means: The Bears hope Parkey can finally fill the void left by Robbie Gould, who the Bears surprisingly cut before the 2016 season. The familiarity level between Parkey and Tabor should make it a smooth transition. The Bears also have to figure out their punter situation. Former sixth-round pick Pat O'Donnell is an unrestricted free agent.

What's the risk: Low-risk move by the Bears. Parkey has experience, and is clearly liked by the special teams coordinator. The only question is why teams (Miami, Cleveland and Philadelphia) have let Parkey walk away in recent years. But Parkey is the least risky Bears' signing so far in free agency.

The Bears agreed to terms on a four-year, $32 million deal with Burton, who played the past four years for the Philadelphia Eagles. Here's a closer look at the signing:

The Bears are counting on Trey Burton thriving in a larger role in Chicago's offense. Chris Williams/Icon Sportswire

Grade: B. Burton, 26, is an athletic, pass-catching tight end who had 23 receptions for 248 yards and five touchdowns last regular season. Burton also had a memorable touchdown pass to quarterback Nick Foles in Philadelphia’s Super Bowl victory.

What it means: The Bears needed to find a tight end to fill respected veteran Zach Miller's role. Miller, who suffered a serious knee dislocation last year, had been Chicago’s best pass-catching tight end. Burton figures to be heavily involved in the passing attack of new Bears head coach Matt Nagy. The Bears invested a second-round pick in tight end Adam Shaheen in 2017, so Shaheen will also be in the mix on offense. It’s unclear what Burton’s arrival means for veteran tight end Dion Sims, who signed with the team last offseason. Sims would be guaranteed $4 million of his $6 million base salary if he’s still on the roster on the third day of the league year (Friday).

What’s the risk: Well, that’s a lot of money for a player with 63 career receptions. The Bears are banking on Burton thriving in a larger role in Chicago, but there’s no guarantee that happens. Best case scenario: The Bears just added two legitimate options for quarterback Mitchell Trubisky. Worst case scenario: The Bears just paid good money for a receiver coming off a torn ACL and a tight end who was a role player in Philadelphia.

Grade: B-plus. Robinson developed into a playmaker for the Jags in 2015-16. The 6-fot-3 receiver caught 80 passes for 1,400 yards and 14 touchdowns in 2016. Still, Robinson only played in one game last season because of a torn ACL. There's a degree of risk attached to the agreement, hence the B+ grade.

What it means: The Bears have one starting wide receiver locked up -- as long as Robinson is medically cleared to return before the start of the regular season. Robinson is Chicago's best receiver since Alshon Jeffery, who left in free agency last year. At just 24, Robinson should be a fixture in the Bears' lineup for years to come, barring another serious health setback. The Bears will add more receivers in the offseason, either in free agency or the draft. There are still medical question marks swirling around wideouts Kevin White and Cameron Meredith. But one starting spot is accounted for with Robinson’s arrival.

What's the risk: Robinson's health, obviously. It's not ideal to sign a free agent coming off a torn ACL, but the Bears' dire situation at wide receiver made it necessary to aggressively pursue Robinson. Now, the Bears have been burned in recent years by signing injury-prone receivers -- Markus Wheaton and Eddie Royal. Robinson, though, is on a different level compared to Wheaton and Royal. He's truly a dangerous weapon in the passing game when healthy, so bringing him in was a risk the Bears were willing to take. Make no mistake, however: Robinson would still be a member of the Jacksonville Jaguars had he not suffered that knee injury in Week 1.

Grade: C. Sowell is veteran depth on the offensive line. He started at guard for the final two games last season, but the Bears mostly viewed Sowell as a reserve player in 2017. However, Sowell does have ample starting experience from his days with the Arizona Cardinals (12 starts) and Seattle Seahawks (nine).

What it means: The Bears have a hole at left guard following Josh Sitton’s departure. Sowell could have an opportunity to compete for a starting job based on how Chicago attacks the offensive line in free agency and the draft, but that’s not a guarantee. In addition, starting right guard Kyle Long is recovering from multiple offseason procedures, and there’s no telling when Long will be medically cleared to join the Bears’ offseason program. Sowell could fill in at right guard until Long is healthy.

What’s the risk: Not much. Sowell is a player the Bears know, and he has plenty of starting experience. The fact that Chicago gave him at two-year deal shows that he’s likely to earn a spot on the final 53-man roster -- health permitting. There’s not much downside to bringing Sowell back on a short deal.